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Sorbus Rupicola
''Sorbus rupicola'', known as rock whitebeam, is a rare shrub or small tree best known from the British Isles but also reported from Norway, Sweden and Russia. Reaching heights of 10 m,''New Flora of the British Isles''; Clive Stace; Third edition; 2011 printing it grows in rocky woodland, scrub and cliffs, usually on limestone. The species reproduces apomictically (asexually via cloned seeds) and was presumably created by autopolyploidysation of the common whitebeam proper (''Sorbus aria s.str.''). It contains a tetraploidal set of chromosomes (2n=4x=68). ''Sorbus rupicola'' is a member of ''Sorbus aria'' agg., which contains 20 subspecies. A key to this aggregate is given in Stace - though be warned Stace states "It is probably impossible to construct a reliable key to the agg."! Stace gives ''Sorbus rupicola'' the following characteristics: * Leaves unlobed or lobed ≤1/20 of the way to the midrib. * Leaves with a single style of teeth or, weakly, two styles of teeth. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trondheimsfjord
The Trondheim Fjord or Trondheimsfjorden (), an inlet of the Norwegian Sea, is Norway's third-longest fjord at long. It is located in the west-central part of the country in Trøndelag county, and it stretches from the municipality of Ørland in the west to the municipality of Steinkjer in the north, passing the city of Trondheim on its way. Its maximum depth is , between Orkland and Indre Fosen. The largest islands in the fjord are Ytterøya and Tautra; the small island of Munkholmen is located near the harbor of Trondheim; and there are several islands at the entrance of the fjord. The narrow ''Skarnsundet'' is crossed by the Skarnsund Bridge. The part of the fjord to the north of the strait is referred to as the ''Beitstadfjorden''. The main part of the Trondheimsfjord is ice-free all year; only Verrasundet, a long and narrow fjord branch in the northern part of the fjord, might be ice covered in winter. The Beitstadfjorden might also freeze over in winter, but only for a few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of Norway. Bouvet Island, located in the Subantarctic, is a dependency of Norway; it also lays claims to the Antarctic territories of Peter I Island and Queen Maud Land. The capital and largest city in Norway is Oslo. Norway has a total area of and had a population of 5,425,270 in January 2022. The country shares a long eastern border with Sweden at a length of . It is bordered by Finland and Russia to the northeast and the Skagerrak strait to the south, on the other side of which are Denmark and the United Kingdom. Norway has an extensive coastline, facing the North Atlantic Ocean and the Barents Sea. The maritime influence dominates Norway's climate, with mild lowland temperatures on the se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, and over six thousand smaller islands."British Isles", ''Encyclopædia Britannica''. They have a total area of and a combined population of almost 72 million, and include two sovereign states, the Republic of Ireland (which covers roughly five-sixths of Ireland), and the United Kingdom of Great Britain and Northern Ireland. The Channel Islands, off the north coast of France, are normally taken to be part of the British Isles, even though they do not form part of the archipelago. The oldest rocks are 2.7 billion years old and are found in Ireland, Wales and the northwest of Scotland. During the Silurian period, the north-western regions collided with the south-east, which had been part of a separate continental landmass. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, Finland to the east, and is connected to Denmark in the southwest by a bridgetunnel across the Öresund. At , Sweden is the largest Nordic country, the third-largest country in the European Union, and the fifth-largest country in Europe. The capital and largest city is Stockholm. Sweden has a total population of 10.5 million, and a low population density of , with around 87% of Swedes residing in urban areas in the central and southern half of the country. Sweden has a nature dominated by forests and a large amount of lakes, including some of the largest in Europe. Many long rivers run from the Scandes range through the landscape, primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the world, with its internationally recognised territory covering , and encompassing one-eighth of Earth's inhabitable landmass. Russia extends across Time in Russia, eleven time zones and shares Borders of Russia, land boundaries with fourteen countries, more than List of countries and territories by land borders, any other country but China. It is the List of countries and dependencies by population, world's ninth-most populous country and List of European countries by population, Europe's most populous country, with a population of 146 million people. The country's capital and List of cities and towns in Russia by population, largest city is Moscow, the List of European cities by population within city limits, largest city entirely within E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clive Stace
Clive Anthony Stace (born 1938) is a British botanist and botanical author. He studied at King's College London, graduated from University of London in 1959 and then studied at the Natural History Museum, London. He was awarded a PhD in 1963. His academic career was based at the University of Leicester, where he held the post of Professor of Plant taxonomy. He is a past president of the Botanical Society of Britain and Ireland from 1987 to 1989. The '' New Flora of the British Isles'', first published in 1991 with subsequent revised editions, is considered the authoritative and comprehensive flora of the British Isles for the late twentieth and early twenty-first century. It aims to include all the taxa that could reasonably found in the British Isles during the year and also to keep up with developments in taxonomy. The second edition was substantially improved over the first in terms of general appearance, typography and illustrations as well as by including chromosome numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apomixis
In botany, apomixis is asexual reproduction without fertilization. Its etymology is Greek for "away from" + "mixing". This definition notably does not mention meiosis. Thus "normal asexual reproduction" of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis, but replacement of the seed by a plantlet or replacement of the flower by bulbils were categorized as types of apomixis. Apomictically produced offspring are genetically identical to the parent plant. Some authors included all forms of asexual reproduction within apomixis, but that generalization of the term has since died out. In flowering plants, the term "apomixis" is commonly used in a restricted sense to mean agamospermy, i.e., clonal reproduction through seeds. Although agamospermy could theoretically occur in gymnosperms, it appears to be absent in that group. Apogamy is a related term that has had various meanings over time. In plants with independent gametophytes (notably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploidy
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by mei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorbus Aria
''Sorbus aria'' ( syn. ''Aria nivea''), the whitebeam or common whitebeam, is a deciduous tree, the type species of the subgenus ''Sorbus'' subg. ''Aria'' of the genus ''Sorbus''. It is native to most of Europe as well as North Africa (Algeria, Morocco, Tunisia) and temperate Asia (Armenia, Georgia). Typically compact and domed, with few upswept branches and almost-white underside of the leaves, it generally favours dry limestone and chalk soils. The hermaphrodite cream-white flowers appear in May, are insect pollinated, and go on to produce scarlet berries, which are often eaten by birds. The cultivars ''S. aria'' 'Lutescens', with very whitish-green early leaves, and ''S. aria'' 'Majestica', with large leaves, have both have gained the Royal Horticultural Society's Award of Garden Merit. The berries are edible when overripe ( bletted). File:Sorbus aria-3420.jpg, Foliage and fruit References aria In music, an aria (Italian: ; plural: ''arie'' , or ''arias'' in commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trends In Ecology And Evolution
A fad or trend is any form of collective behavior that develops within a culture, a generation or social group in which a group of people enthusiastically follow an impulse for a short period. Fads are objects or behaviors that achieve short-lived popularity but fade away. Fads are often seen as sudden, quick-spreading, and short-lived. Fads include diets, clothing, hairstyles, toys, and more. Some popular fads throughout history are toys such as yo-yos, hula hoops, and fad dances such as the Macarena, floss and the twist. Similar to habits or customs but less durable, fads often result from an activity or behavior being perceived as emotionally popular or exciting within a peer group, or being deemed "cool" as often promoted by social networks.Kornblum (2007), p. 213. A fad is said to "catch on" when the number of people adopting it begins to increase to the point of being noteworthy. Fads often fade quickly when the perception of novelty is gone. Overview The specific natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Ecology (journal)
Molecular ecology is a field of evolutionary biology that is concerned with applying molecular population genetics, molecular phylogenetics, and more recently genomics to traditional ecological questions (e.g., species diagnosis, conservation and assessment of biodiversity, species-area relationships, and many questions in behavioral ecology). It is virtually synonymous with the field of "Ecological Genetics" as pioneered by Theodosius Dobzhansky, E. B. Ford, Godfrey M. Hewitt, and others. These fields are united in their attempt to study genetic-based questions "out in the field" as opposed to the laboratory. Molecular ecology is related to the field of conservation genetics. Methods frequently include using microsatellites to determine gene flow and hybridization between populations. The development of molecular ecology is also closely related to the use of DNA microarrays, which allows for the simultaneous analysis of the expression of thousands of different genes. Quantitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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